Apparatus for injecting plasma gas in atmosphere

ABSTRACT

An apparatus for injecting plasma in the atmosphere is provided, including a plurality of dielectric panels ( 13   a,    13   b,    13   c ), and  13   d , which are disposed in parallel at predetermined intervals, a gas supply portion ( 14 ), to which the dielectric panels ( 13   a,    13   b,    13   c , and  13   d ) are fixed and which supplies a gas to spaces between the dielectric panels ( 13   a  and  13   b ), between the dielectric panels ( 13   b  and  13   c ), and between the dielectric panels ( 13   c  and  13   d ), power electrodes ( 15   a,    15   b , and  15   c ), which are linearly installed near the gas supply portion ( 14 ) and between the dielectric panels ( 13   a  and  13   b , between the dielectric panels  13   b  and  13   c , and between the dielectric panels  13   c  and  13   d ), respectively, ground electrodes ( 16   a,    16   b,    16   c , and  16   d ), which are formed in the ends of the dielectric panels ( 13   a,    13   b,    13   c , and  13   d ), respectively, and a high frequency generator ( 17 ), which applies high frequency power to the power electrodes ( 15   a,    15   b , and  15   c ) and the ground electrodes ( 16   a,    16   b,    16   c , and  16   d ).

TECHNICAL FIELD

The present invention relates to an apparatus for injecting plasma inthe atmosphere.

BACKGROUND ART

FIG. 1 is a front view of a conventional apparatus for injecting plasmain the atmosphere. FIG. 2 illustrates the conventional apparatus of FIG.1 viewed from direction A.

As shown in FIGS. 1 and 2, a conventional apparatus for injecting plasmain the atmosphere is manufactured by coupling a pair of dielectricpanels 3 and 3 to a gas supply portion 4 and forming plate-typeelectrodes 2 and 2′ on the surfaces of the dielectric panels 3 and 3′such as to be opposite to each other. In this plasma injectingapparatus, when a high frequency power supply portion 1 applies highfrequency power to both the plate-type electrodes 2 and 2′, and gasflows between the dielectric panels 3 and 3′, the gas turns into plasmawhich is injected from the ends of the dielectric panels 3 and 3′. Thisplasma is injected into an object, such as a liquid crystal display(LCD), a plasma display panel (PDP), a wafer, or the like, to clean theobject.

However, plasma comprised of charged particles is strongly prone to bebound between the dielectric panels 3 and 3′ due to an electrical fieldbetween the plate-type electrodes 2 and 2′. As a result, even if the gassupply portion 4 continuously supplies gas, plasma is not properlyinjected from the dielectric panels 3 and 3′.

To overcome this problem, an effort has been made to increase the amountof plasma by using a high voltage and higher frequency. However, the useof a high voltage causes generation of an arc between plasma and theoutside, an increase in the power consumption, and the like.

DISCLOSURE OF THE INVENTION

The present invention provides an atmospheric plasma injecting apparatuswhich can generate plasma by using less power and effectively inject theplasma into the outside.

The atmospheric plasma injecting apparatus comprises a plurality ofdielectric panels 13 a, 13 b, 13 c, and 13 d, a gas supply portion 14,power electrodes 15 a, 15 b, and 15 c, ground electrodes 16 a, 16 b, 16c, and 16 d, and a high frequency generator 17. The dielectric panels 13a, 13 b, 13 c, and 13 d are disposed in parallel at predeterminedintervals. The dielectric panels 13 a, 13 b, 13 c, and 13 d are fixed tothe gas supply portion 14, which supplies a gas to spaces between thedielectric panels 13 a and 13 b, between the dielectric panels 13 b and13 c, and between the dielectric panels 13 c and 13 d. Thepower-electrodes 15 a, 15 b, and 15 c are linearly installed near thegas supply portion 14 and between the dielectric panels 13 a and 13 b,between the dielectric panels 13 b and 13 c, and between the dielectricpanels 13 c and 13 d, respectively. The ground electrodes 16 a, 16 b, 16c, and 16 d are formed in the ends of the dielectric panels 13 a, 13 b,13 c, and 13 d, respectively. The high frequency generator 17 applieshigh frequency power to the power electrodes 15 a, 15 b, and 15 c andthe ground electrodes 16 a, 16 b, 16 c, and 16 d.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a conventional apparatus for injecting plasmain the atmosphere;

FIG. 2 shows the apparatus of FIG. 1 viewed from direction A;

FIG. 3 is a front view of an apparatus for injecting plasma in theatmosphere according to the present invention; and

FIG. 4 shows the apparatus of FIG. 3 viewed from direction B.

BEST MODE FOR CARRYING OUT THE INVENTION

An apparatus for injecting plasma in the atmosphere according to thepresent invention will now be described in detail with reference to theattached drawings.

Referring to FIGS. 3 and 4, an apparatus for injecting plasma in theatmosphere according to an embodiment of the present invention includesa plurality of dielectric panels, for example, four dielectric panels 13a, 13 b, 13 c, and 13 d, a gas supply portion 14, power electrodes 15 a,15 b, and 15 c, ground electrodes 16 a, 16 b, 16 c, and 16 d, and a highfrequency generator 17. The dielectric panels 13 a, 13 b, 13 c, and 13 dare vertically disposed at a predetermined interval in parallel to eachother and fixed to the gas supply portion 14. The gas supply portion 14supplies a gas to the space between dielectric panels 13 a & 13 b, 13 b& 13 c, and 13 c & 13 d. The power electrodes 15 a, 15 b, and 15 c arelinearly installed between dielectric panels 13 a & 13 b, 13 b & 13 c,and 13 c & 13 d, respectively, such as to be close to the gas supplyportion 14. The ground electrodes 16 a, 16 b, 16 c, and 16 d are formedin the ends of the dielectric panels 13 a, 13 b, 13 c, and 13 d,respectively. The high frequency generator 17 applies high frequencypower to the power electrodes 15 a, 15 b, and 15 c and the groundelectrodes 16 a, 16 b, 16 c, and 16 d.

The dielectric panels 13 a, 13 b, 13 c, and 13 d must have excellentinsulating characteristics.

As described above, the gas supply portion 14 injects a gas into thespace between dielectric panels 13 a & 13 b, 13 b & 13 c, and 13 c & 13d. The gas may be various types of gases, such as, an inert gas (e.g.,argon), oxygen, hydrogen, a compound gas, and the like.

The power electrodes 15 a, 15 b, and 15 c are formed linearly, that is,in the form of wires, between dielectric panels 13 a & 13 b, 13 b & 13c, and 13 c & 13 d, respectively.

The ground electrodes 16 a, 16 b, 16 c, and 16 d are formed in the endsof the dielectric panels 13 a, 13 b, 13 c, and 13 d, respectively. Morespecifically, the ground electrodes 16 a, 16 b, 16 c, and 16 d may becoated on the ends of the dielectric panels 13 a, 13 b, 13 c, and 13 dor inserted into the ends thereof.

The high frequency generator 17 applies high frequency power with afrequency of several to several hundreds of kHz to the power electrodes15 a, 15 b, and 15 c and the ground electrodes 16 a, 16 b, 16 c, and 16d. In this embodiment, power with a 32 kHz frequency is applied thereto.

In this structure, when the high frequency generator 17 applies highfrequency power to the power electrodes 15 a, 15 b, and 15 c and theground electrodes 16 a, 16 b, 16 c, and 16 d, and the gas supply portion4 applies a gas to the space between dielectric panels 13 a & 13 b, 13 b& 13 c, and 13 c & 13 d, the gas turns into conductive plasma. Theconductive plasma is injected from the ends of the dielectric panels 13a, 13 b, 13 c, and 13 d to the outside.

At this time, a high voltage with a high frequency applied to the powerelectrodes 15 a, 15 b, and 15 c flows along with the conductive plasmaproduced between the power electrodes 15 a, 15 b, and 15 c and theground electrodes 16 a, 16 b, 16 c, and 16 d. In other words, an effectwhere a voltage formed in the power electrodes 15 a, 15 b, and 15 cmoves toward the ground electrodes 16 a, 16 b, 16 c, and 16 d appears.Also, a short plasma sheathing is formed on surfaces of the dielectricpanels 13 a, 13 b, 13 c, and 13 d where the ground electrodes 16 a, 16b, 16 c, and 16 d are located. Because plasma outside the plasmasheathing maintains a high voltage, neutral particles existing in theatmosphere in contact with the plasma sheathing turn into plasma due tothe high voltage. As a result, plasma long in the direction of injectionof a gas is obtained. The plasma gas is not easily bound by an electricfield between the power electrodes 15 a, 15 b, and 15 c and the groundelectrodes 16 a, 16 b, 16 c, and 16 d. Thus, the plasma gas injectingapparatus according to the present invention can inject a plasma gasfarther than a conventional plasma injecting apparatus does.

Further, since a plurality of dielectric panels are disposed inparallel, power electrodes are formed at upper sides of the dielectricpanels, and ground electrodes are formed on or in the ends of thedielectric panels, a greater amount of gas can turn into plasma.

As described above, a greater amount of plasma gas can be produced andinjected farther than in a conventional technique, so that ato-be-processed object in a process such as an LCD manufacture, a PDPmanufacture, a semiconductor manufacturing process, a PCB cleaning, apolymer surface modification, or the like, can be effectively cleaned inlarge quantities.

INDUSTRIAL APPLICABILITY

As described above, in an atmospheric plasma injecting apparatusaccording to the present invention, power electrodes are formed at uppersides of dielectric panels, ground electrodes are formed on ends of thedielectric panels, and high frequency power is applied to the spacebetween adjacent electrodes.

Hence, a gas applied to the space between adjacent dielectric panels canturn into plasma in the atmosphere. Since an electric field formed bythe power electrodes and the ground electrodes is in the same directionas the direction of injection of the gas, the plasma gas can spout outfarther than in the conventional technique.

1. An apparatus for injecting plasma in the atmosphere, the apparatuscomprising: a plurality of dielectric panels 13 a, 13 b, 13 c, and 13 d,which are disposed in parallel at predetermined intervals; a gas supplyportion 14, to which the dielectric panels 13 a, 13 b, 13 c, and 13 dare fixed and which supplies a gas to spaces between the dielectricpanels 13 a and 13 b, between the dielectric panels 13 b and 13 c, andbetween the dielectric panels 13 c and 13 d; power electrodes 15 a, 15b, and 15 c, which are linearly installed near the gas supply portion 14and between the dielectric panels 13 a and 13 b, between the dielectricpanels 13 b and 13 c, and between the dielectric panels 13 c and 13 d,respectively; ground electrodes 16 a, 16 b, 16 c, and 16 d, which areformed in the ends of the dielectric panels 13 a, 13 b, 13 c, and 13 d,respectively; and a high frequency generator 17, which applies highfrequency power to the power electrodes 15 a, 15 b, and 15 c and theground electrodes 16 a, 16 b, 16 c, and 16 d.